Optical instrument for determining the direction of travel of air-ships and the like.



0. KRELL.

OPTICAL INSTRUMENT FOR DETERMINING THE DIREGTION 0P TRAVEL OF AIR SHIPSAND THE LIKE.

APPLICATION FILED AUG. 27, 1908.

940,329., Patented Nov. 16, 1909.

iiNrr D S ATES rA EnT OFFICE.

, o'r'ro 31mm,- or ci ARLo'rTENBURG, GERMANY, ASSIGNOR 'rosmmnns-scnucxna'rwnm e. M. B. 11., or BERLIN, GERMANY, A. coaroanrronorcEnmAnY.

or'r-Icnt. I STR MENT FOR DETERMINING tr m DIRECTION or TRAVEL OFAIR-SHIPS l Ann THE LIKE. I

To all whom it may concern:

Be it known that I, Or'ro KRELL, a subject of the German Emperor, andresiding at Charlottenburg, near Berlin, Germany, have invented acertain new and useful Optical Instrument for Determining the Directionof'Travel of Air-Ships and the Like,

ofwhich the following is a specification. J

The subject-matter ofthe present inven-- .10 tion is an opticalinstrument for determining 'the' direction of travel of air-ships,{motor-driven balloons and the like.

When traveling in motor-driven balloons it is not-at once ossible todetermine the 1 5 direction in whic with re ard to the earth. Since themotordriven' alloon, just as any ordinary free balloon, is driven by thewind, themovement ofthe motor-driven balloon is, gen- E erally speakingthe speed which results from 7 he balloon itself due to the f motor andfrom the speed of the wind. Now

the speed of t this resultant only passes through the 1011-gitudinalaxis of the balloon during a calm or when the balloon travelsexactly with or exactly a ainst the wind. In every other- *i'nstance t edirection of motion'of the balloon is at a certain angle to thelongitudinal axis of the motordriven balloon. For

reaching a certain goal it is therefore neces- I 'plained hereafter; lig. 2 is anelevation,-

partly in section, of" an entire instrument according to the invention;Fig. 3 is a sec- 7 tion in the plane w-yirfEig. 2 throu lithe 46prism-box of the instrument, whereas shows in ployed.

' Referrin to I the drawing, and firstly. to

Fig. 1, the Si the balloon due to its motor and from the velocity 'w ofthe wind, this resultant 1' being at an anglew to the longitudinal axisof the balloon.

Specification of Letters-Patent.

w Application filed August 27, 1908. Serial No. 450,558.

the balloon is moving in" which one emperspective the prism which is em-1 rection of the resultant r is here v 50 shown which results frbm the-velocity e of.

Referringto Fig. 2, the instrument consists of -a device whichsimultaneously admitsof'the horizon being observed, as well air-shi andtheir apparent movement. The vertica objective-tube a ofa verticaltelescope and the horizontal object-ivetube I) of a horizontal telescopeare mounted on a frame or box f and have a common eye-piece tube c'provided with an eye-lens 0 The image of the objects on the earth whichproduced in the vertical telescope a is thrown by a glass prism oramirror 77 into Patented Nov. 16, 1909. v

as objects on the earth vertically under the the eye-lens 0, in suchmanner that. this im- Q age only covers half the field of view of thehorizontal telescope A b. horizon can be observed directly through thetelescope Z), 0. In the portion of the field of The points on the visionoccupied by the prism 7) there are lines arranged in such manner thatthey are in vertical planes running parallel to the axis of thehorizontal'telesco )e b. In the example shown in Figs; 3 and 4 theselines are marked on the vertical face of the prism itself, butthey maybe provided otherwise. Now when the balloon moves, the objects on theearth appear to run through thefield of vision of the telescope, and itis only necessary to turn the horizontal telescope until the apparentdirection of motion of the objects on the earth coincides with thedirection of {the lines arranged in the field of vision in thetelescope. The axis of the horizontal telescope will then be situatedexactly in the direction of motion, whether forward or backward, of theballoon, and consequently one can continuouslysee through the telescopethe 'oint on the horizon toward which the ba loon is moving inconsequence of the combined movements due to its own velocityand thevelocity of the wind.

Now'in, order that the oscillations of the balloon may not disturbobservations, with the instrument, the latter is suspended cardanicallyby means ofna universal or balland-socket joint d or in other manner. Inorder to shield the instrument from disturbing motions of the. balloon,one or more gyroscopes 'g are arranged on the instrument which are,driven by electric motors e for example. Approximately the same resultas that obta'in'edby a gyroscope can also be had by the center ofgravity. of the instrument.

being placed as low as possible under the Q g y 640,329

cardanic suspension. Far this purpose a special weight m is placed atthe lowest part of the telescope a. a

NV hat I claim as my invention and desire to secure by Letters Patentis:

1. An optical instrument of the character described having means forobserving simultaneou'sly apoint below and a point on the horizon, andlines within the instrument eoinciding with the direction of theapparent motion of the point below when such di'rection coincides withthe point on the horizon.

I 3'. In an optical instrument, the combinat1on of a frame, a horizontalobjective-tube mounted thereon, a vertical objective-tube:

on said frame, an eyeQpie'ce tube 011 said frame, which is common tosaid objectivetubes, and a glass prism'insaid'frame having a pluralityof lines thereon occupying part 0 the field of vision in said eye-piecetube, said lines being arranged in vertical planes parallel to the axisof said horizontal objective-tube.

4. In an optical instrument, the combination, with cardanic suspensionmeans, of a frame, a horizontal objective-tube v thereon, a verticalobjective-tube on said frame, a common eye-piece tube "on said frame,and a glass prism in said frame having a plurality of lines thereonoccupying part of the field of vision in said eye-piece tube, said linesbeing arranged in vertical, planes parallelto the ax s of saidhorizontal obj ective-tube;

5. In an optical instrument, the combina- .tion, with cardanicsuspension means, of a frame, a horizontal ObJeCtIlVG-tllbG mounted onoccupying part 0 v saldeye-plece tube, said lines being ar-.

ounted thereon,- a vertical objective-tube on said frame, an eye-piecetube on said frame, com

mon' to said objective-tubes,"a glass prism in said frame having aplurality oflins therethe' field of vision in ranged invertical planesparallel to the axis of said horizontal objective-tube, and a gyro scipemounted on said vertical objectivetue. 6. In an optical instrument, thecombination of a frame, a horizontal ob'ective-tube mounted thereon, aVerticalob ectiVe-tube on said frame, a common eye- )iece tube on saidframe, a glass prism in said frame having a plurality of lines thereonoccupying part of the field of vision in said eye-piece tube, said linesbeing arranged in vertical planes parallel to the axis of saidhorizontal objective-tube,.a universal joint attached to said horizontalobjective-tube and to said eyepiece tube for suspending .the-instrw'ment, and an electrically driven gyroscope mounted on said verticalobjective-tubef 7. In an optical instrument, the combination-of a frame,a horizontal objective-tube mounted thereon, a vertical ob'ective-tubeon said frame, an eye-piecev tu on said frame, common to saidobjective-tubes, a

glass prism in said frame having a plurality of,lines thereon'occupyingart of the field of vision in said eye-piece tu e, said lines beingarranged in-vertical planes parallel to the axis of said horizontalobjective-tube, a universal joint attached to said-horizontalobjective-tubeand tot-said eye-piece tube, and a weight attached] to thelower end of said vertical. objective-tube, substantially shown. 1

In testimony whereof I have signed my 'name to this specification in thepresence of two witnesses. I p g OTTO .KRE \Vitnesses v 7 WOLDEMARHAUP'r, ARTHUR SoHRoEDER.

